Polyacrylamide gel electrophoresis (PAGE) remains the standard for protein separation and identification. Nevertheless, the separation strategies that rely on this technique are hampered by (1) inconvenience and irreproducibility in preparation of the variety of gels needed for the separations, (2) limited resolution and dynamic range of biomolecular separations, (3) susceptibility of the polymer to degradation under high electric fields, (4) limitations in their compatibility with mass spectrometric identification of proteins, and (5) relatively large volumes and concentrations of material needed for detection of separated species. Gradient PAGE techniques are recognized to have good resolution and dynamic range, but their utility is greatly hampered by the need for cumbersome gel synthesis protocols and lack of reproducibility.
Thus new devices and methods for separating and analyzing biomolecules are needed.